Threading apparatus for web dryers



G. LEVTCHOUK ETAL 3,508,342

THREADING APPARATUS FOR WEB DRYERS April 28, 1970 Filed April 4, 1968 3Sheets-Sheet 1 GEORGE L-EVTCHOUK JOHN CHARLES BRITTEN 7m 5. MW

ATTORNEY N OE Ap 1970 G. LEVTCHOUK' ETAL 3,503,342

-THREAD ING APPARATUS FOR WEB DRYERS Filed April 4, 1968 s sheets-shed 2INVENTORS.

GEORGE LEVTCHOUK a ileHN CHARLES BRITTEN k25 7W5. M

ATTORNEY p l 1970 G. LEVTCHOUK ETAL 3,508,342

, THREADING APPARATUS FOR WEB DRYERS Filed April 4, 1968 5 Sheets-Sheet5 42 68 36 INVENTORS. GEORGE LEVTCHOUK 8| BgOHN CHARLES BRITTEN 71mm s.MW

ATTORNEY United States Patent THREADING APPARATUS FOR WEB DRYERS GeorgeLevtchouk, Montreal West, Quebec, and John Charles Britten, Pincourt,Quebec, Canada, assignors to Midland-Ross Corporation, Cleveland, Ohio,a corporation of Ohio Filed Apr. 4, 1968, Ser. No. 718,714 Int. Cl. F26b13/06 US. Cl. 34-120 9 Claims ABSTRACT OF THE DISCLOSURE The web tailholding clamp is a wedge type formed of, basically, two parts, a wedgeover which the paper tail or pulp leader strip is placed and animmediately receiving complementary envelope, pocket or sleeve in whichit is positioned. This combination is then threaded by conventionalmeans through a conventional dryer having single or multi-passes.

This invention relates to a threading device for pulp or paper webdryers. More particularly, it relates to a simplified pulp or paper tailholder of the wedge type, that is adapted to hold the forward end of apulp sheet (web) and be pulled through single or multiple pass dryers tostart drying operations.

With increasing speeds and the tendency to totally enclose dryers andthe like pulp and paper treatment apparatus, the threading up must bequickly positively, and automatically performed. The generalconventional tape or rope threading means utilized to seize a web tailor leader strip by stitching it or side seizure and subsequent threadingof a multilevel cylinder dryer or a single pass unit are not fullysatisfactory in that upon not infrequent occasions the tail or leaderholding section exerts unequal transverse tension beyond the cohesivestrength of the wet pulp to tear away, necessitating additionalthreading attempts. The present means, advantageously, are designed inall instances to the pulp tail width and hold the tail or leader endover its transverse width firmly and with equal tension and positivelythroughout the thread ing-up operation. Specifically, the threading-uptail holding means comprises a generally V-shaped pocket or envelope anda generally V-shaped wedge fitting the pocket. The pulp tail is held byand between the two at the start of a threading operation, clampedtherebetween, and the combined unit is led by means of a rope outriggerguide through a dryer. This is a sensitive operation in that the pulp isstill heavy with ponsiderable moisture and must be pulled through one ormore passes of some dryers having pass lengths varying of from about 30to 140 feet long and may comprise as many as up to 13 or more passes.

The invention now will be described in greater detail with reference tothe accompanying drawings, where:

FIGURE 1 is an elevation of a pulp drying apparatus, parts of it beingin section, a plup web former, the threader, and this initial positionof the envelope and Wedge pulp tail holder;

FIGURE 2 is a plan view of a part of the apparatus of FIGURE 1 ahead ofthe pulp feed;

FIGURE 3 is a perspective of the separate sections of the web or pulptail holder;

FIGURE 4 is an elevation of the apparatus adapted to mount the pulp tailholder of FIGURE 3 in an operation position;

FIGURE 5 is a sectional detail of FIGURE 4 showing the simultaneoussevering and seizing of a leader end or pulp tail;

FIGURE 6 is a further detail of FIGURE 5 showing the tab or leaderholder unit being drawn away and into the dryer apparatus;

FIGURE 7 is a sectional detail of one manner of attachment of theseparate components forming the pulp end holder, and their relativeresting positions prior to the one nesting in the other taken on line7-7 of FIGURE 4; and

FIGURE 8 is a further modification of FIGURE 7.

Referring to the drawing and to the general showing of a pulp dryingapparatus in FIGURE 1 a web forming cylinder 9 under vacuum is adaptedto mould and form a pulp web 10. The cylinder is positioned or immersedin a dilute solution of pulp stock 15 which adheres to the cylindersurface being drawn thereto by the vacuum applied to it from within (notshown) thus collecting thereon, as a fiber mat, a pulp web 10. The vat13 is, of course, continuously replenished with a pulp solution.Expressed liquid continues to drop back into the main vat 13 as the pulpweb 10 is compressed and consolidated in its advance about the cylinderby the rolls 16 pressing against its surface. The cylinder 9 rotates onits shaft 12 positioned in receiving bearings 11 located in the vatsides (not shown). The pressed pulp web 10 is then manually led awayfrom the forming cylinder 9 placed under a couch roll 17 to and throughpress rolls .18 and on through the intervening threader apparatus ofthis invention. The aforesaid pulp web forming apparatus 9 is but oneexample of a pulp supply since, obviously, a pulp web also can be formedon and delivered by a Fourdrinier wire.

The wet pulp sheet 10 is initially hand manipulated being forwardedunder the press rolls 16, then to and over an idler roll 29 where it isadjusted to a width re-' ceivable by the threader apparatus. As it isforwarded over the idler rolls 29, 19 and thence over a table orapparatus 20 (holding the threader unit it is cut along its sides bywater jet 28 and led downwardly over a curved front section 21 of thetable 20 between a further pair of complementary driven rolls 23 towaste. Since this invention is directed to a threading-up apparatus of asingle or multi-pass dryer 48 the initial waste of the pulp sheet 10 endis of minimal account inasmuch as the forward portion is severed by atransverse positioned device 26 located within the table 20 and beingactuated by a pneumatic or electrically powered motive means 25. Thetable 20 itself is portable and can be removed from its location oncethe dryer apparatus is threaded with the pulp supply.

The web 10, once started, is led onwardly through the press rolls 18past the side trimming water jets 28, whose action narrows the Web byside sections 30 dropping as waste into bin 31 while it is supported byidler roll 29 to a width acceptable by the threader, at a rate that iscoordinated with the dryer and the threader mechanism associated withit. The threader mechanism generally consists of an outrigger 47(broadly shown in FIGURES l and 2) which is attached through theconnecting line or rope 35 to a pulp web holding wedge 34 of thethreader unit of FIGURE 3, the line or rope passing through sideopenings of the nesting envelope 33. A side trimmed pulp end 10 is thenpassed over the wedge 34 which upon being pulled subsequently nestles inthe receiving cavity of the envelope 33, forming a tight web holdingunit.

The wedge 34 is initially positioned in a recess 22 provided therefor inthe portable table 20. At the proper time both the threader unit and thetrimming knife 26 and the side trimming jets 28 are actuated and theoutrigger 47 pulls the wedge 34 with the pulp Web passing over it intothe waiting sleeve 33, securely clamping the pulp tail in between andhauling it toward the dryer 48. The wedge assembly is then pulled intothe dryer complex 48 over the initial entry roll 46 (separated at themoment from its companion pressure roll) over the several interior dryerrolls 50 and thence out over exterior rolls 51 onto a subsequentcollecting arbor or cutter and layboy (not shown). The threader rope 49,a steel tape in thisvinstance but it could easily be a rope, moves oversheaves 52 mounted on bearings (not shown) located on one end of thedryer rolls 50, 51, and external rolls 55 in an endless fashion, beingcircuitously mounted through the dryer as is generally known. Uponthreading of the dryer apparatus 48 the web width trimmer jets 28 arestopped and moved aside and the threader apparatus is disengaged, thepressure drum of draw unit 46 at the entry end of the dryer is adjustedand the operation is restricted solely to that of feeding and the dryingof the full width of the web roll 10 from the take-off point of thepress rolls 18.

FIGURES 4-6 show in detail the nestled position of the pulp sheetholding wedge 34 in the indenture 22 in which the wedge 34 is positionedby being pulled by the companion pressure drive rolls 18 and 23. Of thelatter rolls, one is driven by an endless belt 56 through a variablespeed gear reduction unit 57 which, in turn, is driven by a power unit58 through an endless belt 59. As stated hereinbefore, the speed of pulpweb feed is correlated to that of the dryer 48 and to its threaderapparatus. The table 20 is also provided with an apron 27 which deflectsany moving pulp sheet into a guideway toward the pick-up and wasteforwarding rolls 23. Further, advantageously there is provided anopposing recess 61 at about the foot of the apron 27, which serves as areceiving recess for the cut-off pulp trimming blade 26. The trimmer 26is preferably covered, being provided with a shield 63. Upon a severingof the web 10 the blade 26 is at once retracted to its originalposition.

On either side of the wedge containing recess 22 and transverselyopposing each other are substantially identical tapered side members orguides 36 over whose extending ends the sleeve or envelope 33 isinitially positioned. It rests there until it is picked up by the Wedge34 when pulled out of its cavity. As particularly shown in FIG- URES and6, upon a starting signal, the web is forwarded to the threading-up unitbeing pull-pushed to the tensioning and take-up rolls 23. Immediatelythereafter, while being held firm to the table surface 21, the knife 26is actuated, severing the web 10 free of the rolls 23. The wedge 34 isimmediately lifted from its resting position in the indenture 22 of thetable raising the web 10 with it to wedge itself in the pocket or sleeve33 which is then lifted or raised off the side guiding members 36: thepulling tape 35 moving through sleeve openings 41 then forms of theparts a unit which is pulled into and through the dryer apparatus 48.FIGURE 6 shows full engagement of the wedge 34 and its complementaryreceiving pocket or sleeve with the web 10 therebetween.

The wedging section 34 is jammed into the envelope 33 by means of thepulling strand 35 moving through transversely spaced sleeve openings 41joining with the wedge at 42. Or, as in FIGURE 8, the end or returningsection of the strand 35 can be passed about end positioned sheave 67and tied into the sleeve as at 68. Upon a pull of the strand 35 thewedge 34 will be brought into the sleeve, the strand 35 moving throughthe openings 41 or 66 effecting a tight wedging of the pulp sheet. Acontinued pull on the strand 35 with the wedge in place in the sleevewill pull the unit off the side members 36 and through the dryer.

The wedge 34 itself further can be provided with a base support uponwhich it slides to be positively directly on its Way into the supportedenvelope 33. The base support or bottom guide 37 is shown in FIGURES 4and 5 and can be a base plate of metal or rigid plastic secured to sideplates 36. It is of such length only to prevent the wedge section 34from not entering the sleeve section 33 and permit pressure of the pulpweb tail or leader strip between wedge 34 and envelope 33.

The receiving envelope 33 as shown in FIGURE 3 is of a generallyV-shaped construction. The envelope 33 has end closures 45 to fullycover the prepared tail section. It is adapted to quickly receive thecomplementary wedge member 34, whose narrow or forward end isstrengthened by means of a rod 40, already having a pulp tail about it.Since the pulp tail is as wet as the remainder of the Web it must bedried also. The envelope 33 is desirably perforated as indicated in thisfigure and in FIGURES 7 and 8 as at 70 0f the drawings. Being perforatedthe drying medium can reach the wet pulp end in the sleeve to dry it andthus strengthen the forward end of the web. The inner Wedge itself canbe perforated but it has been the experience that the perforated sleevewill suffice. Where the dryer is being threaded by the describedapparatus and where it is of aluminum, or of other soft lightweightmetal, and Where vibration or slack in the threading rope may cause thesleeve to come to rest on the surface of an air bed or on a dryer rollthen to prevent scratching or in some manner damaging such surface, thesleeve 33 is provided with at least one plastic plate 39 on FIGURES 7,4, 3 which serves as a runner or rubbing strip. Such a plate is providedon each side, in opposition. If necessary, more can 'be provided toassure greater safety from marring during passage. Of course, someplastics can be used for both the sleeve envelope and the wedge too. Onesuch material can be Teflon, a marketed polymer of carbon tetrafluoride,since it can stand the high temperatures encountered in pulp drying.Another plastic could be a polyurethane polymer. It is necessary,however, to choose one that is tolerant to the high drying temperatureto which the running pulp sheet is subjected. Further, for side supportthe envelope 33 also can be furnished with plastic wheels 69 as shown inFIGURE 8 to safeguard the surface of the rolls over which it willtravel.

What is claimed is:

1. Apparatus for threading web treating apparatus wherein said treatingapparatus is provided with guide means for mechanically threading a webtherethrough, said guide means traveling in a path parallel to thenormal path of said web from the entry to the exit of said treatingapparatus, said web threading apparatus comprising, in combination:means for conveying the web through said web threading apparatus; meansfor trimming at least one longitudinal edge of said web to thereby forma tail of controlled width; a web holding device operatively associatedwith said guide means and having complementary parts through which theleading end of said tail is passed; means for actuating said guide meansto pull said web holding means toward said treating apparatus andthereby actuate said holding means to wedge the leading end of said tailbetween the complementary parts thereof.

2. Apparatus according to claim 1 wherein said guide means comprises anendless rope disposed on one side of the normal web travel path duringits passage through said web treating apparatus, and outrigger meansafiixed to said rope and said web holding means.

3. Apparatus according to claim 2 wherein said endless rope comprises asteel tape which travels over sheaves located adjacent to the edge ofeach internal web treating roll.

4. Apparatus according to claim 1 wherein said trimming means comprisesat least one Water jet positioned along the moving web for shearing offa predetermined portion from the side of said web, and furthercomprising means for severing the excess leading edge of said tail uponactuation of said web holding means.

5. Apparatus for threading Web treating apparatus wherein said treatingapparatus is provided with guide means for mechanically threading a webtherethrough, said guide means traveling in a path parallel to thenormal path of said web from the entry to the exit of said treatingapparatus, said web threading apparatus comprising, in combination:means for conveying the web through said Web threading apparatus; meansfor trimming at least one longitudinal edge of said web to thereby forma tail of controlled width, a web holding device operatively associatedwith said guide means and comprising a V- shaped envelope and agenerally conforming wedge adapted to be positioned in said envelope,the leading end of said tail being adapted to be placed over the wedge;means for actuating said guide means to draw said Wedge into saidenvelope to thereby clamp the leading end of said tail therein.

6. Apparatus according to claim 5 wherein said guide means isoperatively associated with said web holding device by passing over apulley within said wedge and being firmly anchored at its extremity tosaid envelope.

7. A method for threading a Web treating apparatus wherein the "web isfed from a source of supply, through a threading machine and intotreating apparatus and wherein the work is mechanically threaded throughthe treating apparatus comprising the steps of trimming at least onelongitudinal edge of said web to thereby form a tail of controlledwidth; passing the leading end of said tail between complementary partsof a web holding device adapted to engage said tail by wedging actionbetween said complementary parts; actuating a guiding and pulling meanswhich is operatively associated with said web treating apparatus andsaid 'web holding device to thereby actuate the complementary parts ofsaid holding References Cited UNITED STATES PATENTS 201,431 3/1878 Logue24-45 2,944,345 7/1960 Faber 34120 2,946,619 7/1960 Wahl 24l26 3,085,3464/1963 Allander 34120 FOREIGN PATENTS 1,016,301 8/1952 France.

EDWARD J. MICHAEL, Primary Examiner US. Cl. X.R.

